wplua: split the functionality of the load functions into smaller functions

The load functions used to do 3 things:
- push the sandbox function on the stack
- load the file and push it as a function on the stack
- call the sandbox (or the file)

Now there are separate functions to do these 3:
- wplua_push_sandbox
- wplua_load_*
- wplua_pcall

modules/module-lua-scripting/api/api.c

@@ -1427,7 +1427,8 @@ wp_lua_scripting_api_init (lua_State *L)
   wplua_register_type_methods (L, WP_TYPE_IMPL_MODULE,
       impl_module_new, NULL);
 
-  wplua_load_uri (L, URI_API, 0, 0, &error);
-  if (G_UNLIKELY (error))
+  if (!wplua_load_uri (L, URI_API, &error) ||
+      !wplua_pcall (L, 0, 0, &error)) {
     wp_critical ("Failed to load api: %s", error->message);
+  }
 }

modules/module-lua-scripting/api/config.c

@@ -96,12 +96,17 @@ load_file (const GValue *item, GValue *ret, gpointer data)
   lua_State *L = data;
   const gchar *path = g_value_get_string (item);
   g_autoptr (GError) error = NULL;
+  int nargs;
 
   if (g_file_test (path, G_FILE_TEST_IS_DIR))
     return TRUE;
 
   wp_info ("loading config file: %s", path);
-  if (!wplua_load_path (L, path, 0, 0, &error)) {
+
+  nargs = wplua_push_sandbox (L);
+  if (!wplua_load_path (L, path, &error) ||
+      !wplua_pcall (L, nargs, 0, &error)) {
+    lua_settop (L, 0);
     g_value_unset (ret);
     g_value_init (ret, G_TYPE_ERROR);
     g_value_take_boxed (ret, g_steal_pointer (&error));
@@ -134,8 +139,12 @@ wp_lua_scripting_load_configuration (const gchar * conf_file,
   path = wp_find_file (CONFIG_DIRS_LOOKUP_SET, conf_file, NULL);
   if (path) {
     wp_info ("loading config file: %s", path);
-    if (!wplua_load_path (L, path, 0, 0, error))
+    int nargs = wplua_push_sandbox (L);
+    if (!wplua_load_path (L, path, error) ||
+        !wplua_pcall (L, nargs, 0, error)) {
+      lua_settop (L, 0);
       return FALSE;
+    }
     nfiles = 1;
   }
   g_clear_pointer (&path, g_free);

modules/module-lua-scripting/module.c

@@ -40,11 +40,17 @@ static gboolean
 execute_script (lua_State *L, struct ScriptData * s, GError ** error)
 {
   int nargs = 0;
+  nargs += wplua_push_sandbox (L);
+
+  if (!wplua_load_path (L, s->filename, error)) {
+    lua_pop (L, nargs);
+    return FALSE;
+  }
   if (s->args) {
     wplua_gvariant_to_lua (L, s->args);
     nargs++;
   }
-  return wplua_load_path (L, s->filename, nargs, 0, error);
+  return wplua_pcall (L, nargs, 0, error);
 }
 
 G_DECLARE_FINAL_TYPE (WpLuaScriptingPlugin, wp_lua_scripting_plugin,

modules/module-lua-scripting/wplua/wplua.c

@@ -117,6 +117,11 @@ wplua_enable_sandbox (lua_State * L, WpLuaSandboxFlags flags)
   g_autoptr (GError) error = NULL;
   wp_debug ("enabling Lua sandbox");
 
+  if (!wplua_load_uri (L, URI_SANDBOX, &error)) {
+    wp_critical ("Failed to load sandbox: %s", error->message);
+    return;
+  }
+
   lua_newtable (L);
   lua_pushliteral (L, "minimal_std");
   lua_pushboolean (L, (flags & WP_LUA_SANDBOX_MINIMAL_STD));
@@ -125,11 +130,17 @@ wplua_enable_sandbox (lua_State * L, WpLuaSandboxFlags flags)
   lua_pushboolean (L, (flags & WP_LUA_SANDBOX_ISOLATE_ENV));
   lua_settable (L, -3);
 
-  if (!wplua_load_uri (L, URI_SANDBOX, 1, 0, &error)) {
+  if (!wplua_pcall (L, 1, 0, &error)) {
     wp_critical ("Failed to load sandbox: %s", error->message);
   }
 }
 
+int
+wplua_push_sandbox (lua_State * L)
+{
+  return (lua_getglobal (L, "sandbox") == LUA_TFUNCTION) ? 1 : 0;
+}
+
 void
 wplua_register_type_methods (lua_State * L, GType type,
     lua_CFunction constructor, const luaL_Reg * methods)
@@ -177,17 +188,9 @@ wplua_register_type_methods (lua_State * L, GType type,
 
 static gboolean
 _wplua_load_buffer (lua_State * L, const gchar *buf, gsize size,
-    const gchar * name, int nargs, int nres, GError **error)
+    const gchar * name, GError **error)
 {
   int ret;
-  int sandbox = 0;
-  int args_top = lua_gettop (L);
-
-  /* wrap with sandbox() if it's loaded */
-  if (lua_getglobal (L, "sandbox") == LUA_TFUNCTION)
-    sandbox = 1;
-  else
-    lua_pop (L, 1);
 
   /* skip shebang, if present */
   if (g_str_has_prefix (buf, "#!/")) {
@@ -200,26 +203,14 @@ _wplua_load_buffer (lua_State * L, const gchar *buf, gsize size,
   if (ret != LUA_OK) {
     g_set_error (error, WP_DOMAIN_LUA, WP_LUA_ERROR_COMPILATION,
         "Failed to compile: %s", lua_tostring (L, -1));
-    lua_pop (L, nargs + sandbox + 1);
+    lua_pop (L, 1);
     return FALSE;
   }
-
-  /* push sandbox() and the chunk below the arguments */
-  lua_rotate (L, args_top, -nargs);
-
-  ret = _wplua_pcall (L, nargs + sandbox, nres);
-  if (ret != LUA_OK) {
-    g_set_error (error, WP_DOMAIN_LUA, WP_LUA_ERROR_RUNTIME,
-        "Runtime error while loading '%s'", name);
-    return FALSE;
-  }
-
   return TRUE;
 }
 
 gboolean
-wplua_load_buffer (lua_State * L, const gchar *buf, gsize size,
-    int nargs, int nres, GError **error)
+wplua_load_buffer (lua_State * L, const gchar *buf, gsize size, GError **error)
 {
   g_return_val_if_fail (L != NULL, FALSE);
   g_return_val_if_fail (buf != NULL, FALSE);
@@ -227,12 +218,11 @@ wplua_load_buffer (lua_State * L, const gchar *buf, gsize size,
 
   g_autofree gchar *name =
       g_strdup_printf ("buffer@%p;size=%" G_GSIZE_FORMAT, buf, size);
-  return _wplua_load_buffer (L, buf, size, name, nargs, nres, error);
+  return _wplua_load_buffer (L, buf, size, name, error);
 }
 
 gboolean
-wplua_load_uri (lua_State * L, const gchar *uri, int nargs, int nres,
-    GError **error)
+wplua_load_uri (lua_State * L, const gchar *uri, GError **error)
 {
   g_autoptr (GFile) file = NULL;
   g_autoptr (GBytes) bytes = NULL;
@@ -253,12 +243,11 @@ wplua_load_uri (lua_State * L, const gchar *uri, int nargs, int nres,
 
   name = g_path_get_basename (uri);
   data = g_bytes_get_data (bytes, &size);
-  return _wplua_load_buffer (L, data, size, name, nargs, nres, error);
+  return _wplua_load_buffer (L, data, size, name, error);
 }
 
 gboolean
-wplua_load_path (lua_State * L, const gchar *path, int nargs, int nres,
-    GError **error)
+wplua_load_path (lua_State * L, const gchar *path, GError **error)
 {
   g_autofree gchar *abs_path = NULL;
   g_autofree gchar *uri = NULL;
@@ -274,5 +263,17 @@ wplua_load_path (lua_State * L, const gchar *path, int nargs, int nres,
   if (!(uri = g_filename_to_uri (abs_path ? abs_path : path, NULL, error)))
     return FALSE;
 
-  return wplua_load_uri (L, uri, nargs, nres, error);
+  return wplua_load_uri (L, uri, error);
+}
+
+gboolean
+wplua_pcall (lua_State * L, int nargs, int nres, GError **error)
+{
+  int ret = _wplua_pcall (L, nargs, nres);
+  if (ret != LUA_OK) {
+    g_set_error (error, WP_DOMAIN_LUA, WP_LUA_ERROR_RUNTIME,
+        "Lua runtime error");
+    return FALSE;
+  }
+  return TRUE;
 }

modules/module-lua-scripting/wplua/wplua.h

@@ -52,6 +52,7 @@ lua_State * wplua_new (void);
 void wplua_free (lua_State * L);
 
 void wplua_enable_sandbox (lua_State * L, WpLuaSandboxFlags flags);
+int wplua_push_sandbox (lua_State * L);
 
 void wplua_register_type_methods (lua_State * L, GType type,
     lua_CFunction constructor, const luaL_Reg * methods);
@@ -87,11 +88,11 @@ WpProperties * wplua_table_to_properties (lua_State *L, int idx);
 void wplua_properties_to_table (lua_State *L, WpProperties *p);
 
 gboolean wplua_load_buffer (lua_State * L, const gchar *buf, gsize size,
-     int nargs, int nres, GError **error);
-gboolean wplua_load_uri (lua_State * L, const gchar *uri, int nargs, int nres,
-    GError **error);
-gboolean wplua_load_path (lua_State * L, const gchar *path, int nargs, int nres,
     GError **error);
+gboolean wplua_load_uri (lua_State * L, const gchar *uri, GError **error);
+gboolean wplua_load_path (lua_State * L, const gchar *path, GError **error);
+
+gboolean wplua_pcall (lua_State * L, int nargs, int nres, GError **error);
 
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(lua_State, wplua_free)